Does it make sense to use alternative quantizations of QAT models? [D]

From TF's website:

Quantization aware training emulates inference-time quantization, creating a model that downstream tools will use to produce actually quantized models.

So is it designed to work with a very specific quantization method (for Gemma-4, presumably, Google's own)? Or would it make sense to use alternative quantization methods?

According to the benchmarks unsloth released, its (alternative) quantizations of Gemma-4-QAT are closer to the QAT fine-tunes, but is it a good thing, or does it defeat the purpose of QAT?